Ski device

ABSTRACT

I have devised a force modulating device, for use as a force modulating member of a ski device, in which I have made a first member thereof to be movably interconnected with a body member of the force modulating device and I have disposed therebetween fluid pressure means for floating the first member with respect to the body member and controlling the relative movement between such two members. The controlled movement of the first member relative to the body member provided by the fluid pressure means causes impact forces that are imparted to a ski device incorporating the present invention to be so modulated as to allow for good ski performance in terms of spring-action, smooth ride, handling, and service life. The fluid pressure medium of the fluid pressure means can be a gas, a liquid or a combination gas and liquid. The fluid pressure means can be provided with means for communicating with a fluid pressure supply source, illustratively located off of the ski, permitting external manual or automatic adjustments or changes to the fluid pressure means to be made after a ski device incorporating this invention has been fabricated so as to optimize the force modulating capability of the ski device for a particular user load and use. The force modulating device can be altered in its damping characteristics by a manually adjustable vibration damping assembly disposed between the movable and body members of the device. Mechanical and electrical control means can be adapted to the ski device incorporating this invention so as to cooperate with the fluid pressure means of the force modulating device in controlling the relative movement between the movable and body members of such force modulating device.

CROSS-REFERENCE TO RELATED APPLICATION

This is a division of copending application Ser. No. 7/385,729 filedJul. 26, 1989 now U.S. Pat. No. 5,156,413.

BACKGROUND OF THE INVENTION

This invention relates generally to ski devices and particularly to skidevices that are adapted to modulating the impact forces to which theyare exposed.

Materials are commonly added to ski devices for the purpose of alteringthe impact forces to which such devices are exposed. See, for example,U.S. Pat. Nos. 3,861,699 (fiber reinforced plastic honeycomb core havinghollow tubular members and upper and lower foam filled corrugations);U.S. Pat. No. 4,065,150 (ski body composed of a composite material ofcontinuous reinforcing fibers embedded in a matrix of an elastomermodified plastic foam); U.S. Pat. No. 4,405,149 (ski provided internallywith two or more strips of constrained viscoelastic material); U.S. Pat.No. 4,420,523 (rigid core with a number of elastomer strips reinforcedwith twisted fiber bundles); U.S. Pat. No. 4,438,946 (ski body providedwith a stressed viscoelastic band); U.S. Pat. No. 4,563,020 (metal diskon low friction collar shifts between a pair of foam rings in a housingattached to the tip of the ski); U.S. Pat. No. 4,627,635 (damping unitof ski has viscoelastic means interposed between alternatingone-end-free, one-end-secured flexible strips); U.S. Pat. No. 4,647,063(cellular core structure). These devices have generally been found to belimited in their ability in altering such forces. They are also limitedin the adjustments that can be made to their impact force alteringcharacteristics once the ski device has been fabricated so as to makethe device readily adaptable for a particular user load and use.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a ski device with goodmeans for modulating the impact forces to which the ski is exposed.

Another object of the present invention is to provide a ski device withimpact modulating means that can, after fabrication of the device, byexternal manual or automatic adjustment, be readily tuned in its impactmodulating characteristics so as to make the ski device adaptable for aparticular user load and use.

Another object of the present invention is to provide an extremelyeffective means for isolating the skier and/or portions of the skidevice from the severity of impact forces to which the ski is exposed.

Another object of the present invention is to provide a ski device withmeans for so modulating impact forces transmitted to the ski as to allowfor good ski performance in terms of spring-action, smooth ride,handling and service life.

To achieve these and other objects, I have devised for use as a forcemodulating member of a ski a force modulating device in which I havemade a movable member thereof to be movably interconnected with a bodymember of the force modulating device and I have disposed therebetweenfluid pressure means for floating the movable member with respect to thebody member and controlling the relative movement between such twomembers. The controlled movement of the movable member relative to thebody member provided by the fluid pressure means causes impact forcestransmitted to a ski device incorporating the present invention to be somodulated as to allow for good ski performance in terms ofspring-action, smooth ride, handling, and service life.

Illustratively, the force modulating device can be so incorporated intothe ski device that its movable member provides a top or bottom surfaceto the ski device. Alternatively, the entire force modulating device canbe incorporated within the ski. Incorporating more than one such deviceof like or different fluid pressure means can further tailor the dynamicresponse of the ski to impact forces.

The fluid pressure means can be provided with means for communicatingwith a fluid pressure supply source, illustratively located off of theski. Such communication means readily permit manual or automaticpressure adjustments or fluid pressure medium changes to be made to thefluid pressure means, after a ski device incorporating this inventionhas been fabricated, so as to better tailor the force modulatingcapability of the ski device to a particular user load and use.

The force modulating device of the present invention can be altered inits force modulating characteristics by a manually adjustable vibrationdamping assembly disposed between the movable and body members of thedevice. Mechanical and electrical control means can be adapted to theski device incorporating this invention so as to cooperate with thefluid pressure means of the force modulating device in controlling therelative movement between the movable and body members of the forcemodulating device.

BRIEF DESCRIPTION OF DRAWINGS

These and other objects, features, and advantages of the invention willbe more readily apparent from the following description of theillustrative embodiments of the invention in which:

FIG. 1 is an exaggerated side view taken through a center section of oneillustrative embodiment of the ski device of the present invention.

FIG. 2 is an exaggerated cross-sectional view of the FIG. 1 ski devicetaken along phantom line 2--2.

FIG. 3 is an exaggerated side view taken through a center section of oneillustrative fabrication embodiment of the ski device of the presentinvention.

FIG. 4 is an exaggerated top view of the FIG. 3 ski device.

FIG. 5 is an exaggerated cross-sectional view similar to a crosssectional view of the FIG. 1 device taken along either phantom line 5--5illustrating another embodiment of the invention.

FIG. 6 is a schematic side view of another illustrative embodiment ofthe ski device of the present invention.

FIG. 7 is a schematic diagram, partly in functional block diagram form,of an electronic control system with transducer feedback adapted for usewith the FIG. 6 ski device.

FIG. 8 is a schematic perspective layout, partly in block diagram form,of the FIG. 6 ski device with FIG. 7 electronic control system.

FIG. 9 is an exaggerated cross-sectional view of yet anotherillustrative embodiment of the ski device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a ski device 10 of the present invention comprising abottom member 100, a top member 200, and a pressure chamber 300.

Bottom member 100 defines in a portion thereof a housing 110 forming abore 120 on an inside surface.

Housing 110 receives the top member 200, as hereinafter described, whichcooperates with the wall of bore 120 to define the pressure chamber 300,also hereinafter described.

Fluid pressure medium from a fluid pressure supply source (not shown),illustratively located off of the ski, is communicated to pressurechamber 300 via an inlet port 310 (not shown), prior to skiing such thattop member 200 moves from point A toward point B within bore 120 ofhousing 110.

Impact forces applied to ski device 10 urge top member 200 toward oraway from bottom member 100. Consequently, pressure chamber 300 isvaried by this relative movement of top member 200 and bottom member 100causing the impact forces to be so modulated as to allow for good skiperformance in terms of spring-action, smooth ride, handling, andservice life.

In accordance with the invention, bottom member 100 comprises oak,okoume, fir, spruce or other woods; rigid foam in acrylic, polyurethane,epoxy, rigid p.v.c. and other resins; hollow cores infibre-reinforced-resin box-structure; honeycombed material such asaluminum; metal; or other ski construction materials (hereinafter,collectively, "Ski Construction Materials") configured so as towithstand the forces the bottom member must bear during use. Thesematerials can be used alone or in varying permutations and combinationsso as to provide a desired stiffness to the ski device. The housing 110portion of the bottom member too is made from Ski ConstructionMaterials, selected, in addition to the stiffness criteria, so as tocontain the fluid pressure medium in the pressure chamber as hereinafterdescribed and preferably also so as to accommodate the compressivestresses and strains experienced in various portions of the ski devicealong the thickness of the ski device. If a stiff material, such as anon-yielding metal is used for housing 110, a gap Z can be provided inthe bottom member 100 for accommodating the above compressive stressesand strains. In this case, a resilient backing 112, such as shown inFIG. 1, can be placed in the gap to provide a continuous surface so asto enhance the structural strength and aerodynamic performance of theski while accommodating the aforementioned compressive stresses andstrains.

As shown in FIG. 2, bottom member 100 further comprises a low frictionrunning surface 130, edges 140, and rubber gaskets 150, 160.Illustratively, low friction running surface 130 is an extruded sheet ofpolyethylene material, typically secured to a surface 111 below housingportion 110. Alternatively, one or more layers of Ski ConstructionMaterials can be disposed and adhesively secured between running surface130 and surface 111. These materials can be used alone or in varyingcombinations so as to provide a desired stiffness to the ski device.Edges 140 are preferably steel strips secured to the bottom edges of lowfriction running surface 130. Rubber gasket 150 and rubber gasket 160are fixedly seated along an inside shoulder 152 and an outside shoulderregion 162, respectively, of housing 110 so as to absorb vibrationscreated whenever top member 200 comes into contact with said inside andoutside shoulders.

Top member 200 comprises a core assembly 210 slidably disposed withinbore 120 and a top layer 260 engageable with core assembly 210.

Top layer 260 comprises a solid substrate 262 and a protective cosmeticlayer 264. Illustratively, solid substrate 262 comprises a metal.Alternatively, solid substrate comprises one or more other layers of SkiConstruction Materials configured so as to withstand the forces the toplayer must bear during use. These materials can be used alone or invarying permutations and combinations so as to provide a desiredstiffness to the ski. Illustratively, protective cosmetic layer 264 is asheet of plastic.

Core assembly 210 comprises one or more core layers of Ski ConstructionMaterials, which can be used alone or in varying permutations andcombinations so as, in addition to providing a desired stiffness to theski, to contain fluid pressure medium in the pressure chamber ashereinafter described. Core assembly 210 extends substantially acrossthe opening of bore 120 so as to be movable within the bore and extendsinto the bore.

Core assembly 210 terminates away from top layer 260 in a sidewardlyextending flange 230. The flange sidewardly extends into an outwardlystepped portion 124 of bore 120 formed about a lower section of bore 120for the purpose of movably receiving sidewardly extending flange 230.The flange is dimensioned so as to be moveable from Point A to Point Bwithin said outwardly stepped portion 124 of bore 120. A top side 232 offlange 230 is shaped so as to engage rubber gasket 150, which isadhesively seated against inside shoulder 152 of the housing 110, whentop side 232 of flange 230 is situated at Point B therein. Shoulder 152substantially prevents core assembly 210 from moving upwardly of Point Band thus acts to retain the core assembly 210 within bore 120. A bottomside 234 of flange 230 near inlet port 310 to pressure chamber 300 istapered inwardly so as to allow fluid pressure medium from a fluidpressure supply source to freely communicate with pressure chamber 300when core assembly 210 is seated near bottom portion of housing 110.

Pressure chamber 300 has one end connected to inlet port 310.Alternatively, pressure chamber 300 can be designed to operate withoutsuch inlet port 310. Illustratively, the inlet port is a pressure valve.The inlet port is shown in FIG. 2 to be open at a first end to pressurechamber 300 and at a second end to an outside surface of ski device 10,preferably a side terminating away from the other of the two ski devicesbeing used, so as to be adaptable for connection to a fluid pressuresupply source (not shown), which illustratively is located off of theski. Inlet port 310 readily permits manual or automatic pressureadjustments or other changes to be made to the fluid pressure means,including charging or changing of the fluid pressure medium, after thedevice has been fabricated so as to better tailor the force modulatingcapabilities of the ski device for a particular user load and use.

Preferably, structural enhancement means are provided to the ski devicefor the purpose of resisting the core assembly from rolling, pitching,or yawing within the pressure chamber during turning motions of the ski.One example of such a resistance means is providing pressure chamber 300with one or more vertical guide posts 191 extending upwardly from bottomportion of housing 110 into pressure chamber 300 for slidably matingwith openings 291 provided in the core assembly 210. The guide posts soserve as a core assembly guide within bore 120 in the housing as toprovide resistance to rolling, pitching, or yawing of the core assemblywithin the pressure chamber.

Pressure chamber 300 is charged with a fluid pressure medium to apredetermined pressure so as to upwardly bias top member 200 and urgesidewardly extending flange 230 toward rubber gasket 150 and insideshoulder 152 of housing 110. Illustratively, the fluid pressure mediumis compressed air. Alternatively, any gas or liquid at the temperatureranges that the ski is to be used with compressibility characteristicscan be used. An example of another gas is nitrogen. Examples of someliquids that can be used as the fluid pressure medium include water(above freezing point, alone or in combination with solutes, but belowfreezing, in combination with solutes such as alcohol, glycerol,ethylene glycol), mineral oils, emulsions, water-based glycols, orsynthetic fluids such as phosphate esters or chlorinated hydraulics.

Preferably, pressure chamber 300 is provided with a fluid bag or otherfluid containment means (not shown) which extends inside and along thepressure chamber for receiving the fluid pressure medium contained bythe pressure chamber. If pressure chamber is designed to operate withinlet port 310, the first end of the inlet port is molded integral withsuch fluid containment means. Alternatively, the fluid pressure mediumis received and contained by the walls of pressure chamber 300 and aresilient sealing member 280 illustratively comprising a U-shaped,lip-type pressurized fluid tight seal which cooperates with the wall ofbore 120 so as to substantially form pressure chamber 300. In thisalternative and as shown in FIG. 2, resilient sealing member 280 isfitted into a slot 282 formed in a wall of core assembly 210 which urgesit against the wall of bore 120 so as to seal pressure chamber 300 andat the same time serve as a top member 200 guide within bore 120 inhousing 110. The U-shaped lip portion of the resilient sealing member280 allows fluid pressure medium to press the resilient sealing memberagainst the wear surfaces. Alternatively, resilient sealing member canbe fitted into a slot formed in the bore 120 side of housing 110 andurged against core assembly 210. Resilient sealing member 280 isselected to be compatible with the pressurized fluid medium housed bypressure chamber 300 and to seal the fluid pressure medium in thepressure chamber under the operating parameters of the pressure chamber.It will be appreciated that as yet another alternative, cooperation ofthe fluid bag and resilient sealing member 280 can contain the fluidpressure medium within pressure chamber 300.

The fluid bag is chosen for its compatibility with the fluid pressuremedium which it will contain under the conditions at which such fluidpressure medium in the pressure chamber will be charged. Preferably, thefluid bag is pear shaped or similarly tapered on the portion of thefluid bag adjacent to top member 200 so that in pressure chamber 300,the movement of top member 200 within bore 120 provides optimum pressuredistribution without degrading the sidewalls of the fluid bag.Illustratively, the fluid bag is made of elastomeric material such asnitrile rubber. Alternatively, any other fluid bag meeting thecompatibility and operability conditions set forth above can be used.

Illustratively, and as shown in FIG. 1, top member 200 extendslengthwise along a middle portion of ski device 10 between front andtail end portions of the ski. Such middle portion includes the portionof the ski device occupied by boot and binding of a skier.Alternatively, top member 200 can extend lengthwise along any portion ofski device 10. It will also be appreciated that as hereinafter describedmore than one top member 200--housing 110--pressure chamber300--combination can be used with the present invention. For example, atop member of a first combination can be located between phantom lines10--10 and 11--11 of FIG. 1 so that top surface of the top member is incontact with the snow and a top member of a second combination can belocated between phantom lines 12--12 and 13--13 so that top surface ofthe top member is similarly in contact with the snow. In this example,alternatively, the top surfaces can face upward. Appropriate weightingof the top and bottom members produces the desired impact response. Aswill be appreciated, each of these and other top member configurationscan be used alone or in varying combinations to provide ski device 10with a desired response to impact forces.

Referring to FIG. 2 in combination with FIG. 1, top layer 260 of topmember 200 extends widthwise substantially across the width of skidevice 10. Alternatively, top layer 260 can at the portion of ski device10 occupied by boots and bindings of a skier extend substantially acrossthe width of the ski device and beyond such points extend across anywidth of the ski device as is desirable for a particular skiapplication. Core assembly 210 of top member 200 extends between andinto bore 120 of bottom member 100.

In this illustration, the top portions of ski device 10 that are notincluded as part of top member 200 (i.e., the top portions of the tipand tail portion of the ski device) are understood to be part of bottommember 100. For example, protective cosmetic layer 180 of bottom member,which is analogous in function and make-up to protective cosmetic layer264 of the top member is fabricated as part of the bottom member.

Illustratively, in a 195 cm length ski device having about a 70 mmwidth, starting at about 840 mm from the tip of the ski device isdefined housing 110 forming bore 120 having an outer opening of slightlygreater than about 482.6 mm in length, 47.63 mm in width, 2.38 mm indepth for about a 22,986 square mm opening and an outwardly steppedportion 124 of bore 120 of slightly greater than about 604.8 mm inlength, 52.39 mm in width, 4.76 mm in depth for about a 31,684 square mmopening. About 0.79 mm thick rubber gaskets 150, 160 are adhesivelyseated on either side of the outer opening. Slidably disposed within thebore is a core assembly 210 of about 7.14 mm in depth including a flange230 portion depth of about 1.59 mm, the flange extensions away from thecore assembly being, toward the tip and tail section of the ski, abouthalf of 122.23 mm each, and toward the sides of the ski, about half of4.76 mm each. The stroke length of the core assembly in the bore, thatis, the extension of core assembly 210 into the bore, is about 6.35 mmat maximum and 4.76 mm at minimum extension. Top layer 260, a metal, oftop member 200 extending about 609.6 mm in length starting at about 840mm from the tip of the ski device has about a 70 mm width and is severalmm in depth. A gap formed between top layer 260 and rubber gasket 160 isabout 1.59 mm when the core assembly is at minimum extension into thebore. The gap formed between Points A and B is about 1.59 mm. The volumeof the pressure chamber varies with minimum and maximum extension of thecore assembly into the bore between about 75,453 cubic mm and 25,158cubic mm, respectively. Compressed air is introduced into pressurechamber 300 so that the air is under a pressure of about 20 psi.

Illustratively, ski device 10 is fabricated as shown in FIGS. 3,4 usingthe well-known laminated or bonded cross-section process. Alternatively,the device can be formed using wet wrap or torsion cell or otherprocesses or combinations of processes. Illustratively, housing 110portion of bottom member 100 is formed from steel. Other suitablematerials can be chosen so long as appropriately dimensioned to receive,hold and be compatible with the fluid pressure medium which it willcontain under the conditions at which such fluid pressure medium in thepressure chamber will be charged. In the above illustrated ski device,housing 110 has a ceiling, a floor and walls welded together from a toppanel 190, a bottom panel, and side and tip and tail panels,respectively, of greater than about 2.38 mm thickness each. A taphole312 is formed in a first side panel of the housing for accommodatinginlet port 310.

Prior to welding of the housing, a window X is opened in top panel 190of the housing 110, dimensioned to have the area of the bore. Thethickness of this top panel defines the depth of the outer opening ofbore 120 for receiving core assembly 210. The side panels of window Xare polished to promote movement of core assembly 210 (the contactsurfaces of which are also polished) thereagainst. Rubber gasket 150 isadhesively seated against the inner side of the top panel, i.e., insideshoulder 152 side of housing 110. Rubber gasket 160 is adhesively seatedagainst the outer side of the top panel, i.e., outside shoulder 162 sideof housing 110. With core assembly 210 disposed partly through window X,top layer 260 is adhesively secured to the core assembly. In this way,top member 200 is built into the top panel of the housing. A fluid bag320 is secured to the inner side of the bottom panel of the housing sothat its valve (i.e., inlet port 310) fits through taphole 312 in afirst side panel of housing 110. With side panels of the housing inplace, the edges of the housing panels are then welded together.

Bottom member 100 of the ski device is formed using laminated techniquesand is provided with a window Y for receiving and holding the housing.As shown in FIG. 4, at the tip and tail sides of window Y are providedwindow extensions Z which are tapered outwardly (as shown in FIG. 3) soas to form a gap of about 15 mm at the opening and about half thatamount at the base of the gap when the housing is put into window Y.Such gap, which receives resilient backing 112, allows for accommodationof the compressive stresses and strains experienced along the thicknessof the bottom member 110 when the camber of the bottom member isdownloaded.

The ski device is finally assembled in a suitable mold in the followingmanner. Bottom member 110 of the ski device is positioned in the mold.The bottom and side surfaces of the housing, the resilient backing 112,the contact surface of the rubber gasket 160 extending outwardly fromthe top panel, and window Y, with Z extension, are coated with asuitable adhesive and the housing and the resilient backing are placedinto the window. When all parts of the ski are prepared and positioned,the mold is closed. The assembly is subjected to suitable heat andpressure until the parts of the ski device are securely bonded to eachother. The ski is then put through a finishing process.

Prior to use, pressure chamber 300 is charged with air, illustrativelyto about 20 psi so as to upwardly bias core assembly 210 within skidevice 10. (If the invention is used without an inlet port, the pressurechamber is charged to this pressure during the manufacture of the deviceat the factory.) As pressure chamber 300 is charged, core assembly 210is urged upwardly within ski device 10 from Point A toward Point B. Asecond biasing pressure within pressure chamber 300 is defined when skidevice 10 is downloaded with the weight of the skier.

During skiing, when ski device 10 hits a disturbance such as a bump,bottom member 100 rises rapidly. Without this invention, the impactforce transmitted to the skier generally would be considerable. In thisinvention, generally, the only force transmitted to the skier is thatrequired to compress pressure chamber 300 far enough for bottom member100 to ride over the bump. This force causes the skier to accelerateupwards but generally at a much smaller rate than would otherwise beexperienced.

When bottom member goes into depression, the force in pressure chamber300, acting on the relatively light unsprung mass of bottom member 100forces the bottom member downwardly at a rapid rate so that it generallyreaches the base of the depression almost before the relatively muchlarger mass of the skier has, owing to his inertia, had time to begin todescend. Since the variations in the pressure chamber 300 force oversuch deflections are relatively small, the downward acceleration of theskier supported by the pressure chamber generally is correspondinglymoderate as compared with that which, under the influence of gravity, itwould be if there were no pressure chamber.

When the disturbance has passed, whether it is a bump or a depression,the subsequent motion of the skier generally as his free vibration onthe pressure chamber, the acceleration being small. As shown in FIG. 5,by providing a vibration damping assembly 500 to top member 200, thisvibration can be rapidly reduced to zero.

FIG. 5 shows a variation on the FIG. 2 device wherein around phantomline 5--5 and phantom line 5--5 of the FIG. 1 ski device (i.e., theportion of the ski device outside the area occupied by the boot andbinding), the width of top member 200 is narrower than the width of theski device and wherein further bottom member 100 extends upwardlyalongside such top member portions of narrower width to form sidewalls190 thereto. As shown in FIG. 5, top layer 260 of top member 200 furthercomprises, illustratively at such top member portions of narrower width,a soft block 510 secured to solid substrate 262 of top layer 260,threaded bolts 520,522, with heads 560,562, first washers 530, 532,second washers 540,542, nuts 550,552, and a plate member 590. Soft block510 is made from damping material, illustratively, comprising an elasticnatural rubber impregnated with asbestos fibers for friction and heatresistance, friction modifiers, such as oils to give the desiredfriction coefficient, and powdered metal to improve frictionperformance. Soft block is disposed between solid substrate 262 andplate member 590, illustratively metal. Openings 570,572 are formed intop layer 260 for accommodating threaded bolts 520,522 such that topends of the bolts extend out of top layer 260. First washers 530,532 areplaced between the heads 560,562 and plate member 590. Top ends of boltsare provided with second washers 540,542 held in place by nuts 550,552.The top ends of bolts are provided with screwdriver slots 580,582 whichare used for adjustment purposes. Alternatively, nuts 550,552 can bedirectly adjusted with a suitable wrench. Adjustment of bolts 520,522cause a variation in the axial compression of soft block 510 betweensolid substrate 262 and plate member 590. As the axial compressionincreases, the soft block is urged against sidewalls 190, causing anincreased amount of friction between the soft block 510 and the surfaceof sidewalls 190. Several bolt arrangements can be used with soft block510 so as to enhance the adjustment capability of the vibration dampingassembly 500.

As discussed in connection with FIG. 2, pressure chamber 300 of the skidevice can be charged with a liquid fluid pressure medium. Becauseliquids are only slightly compressible, the result would be a relativelystiff or hard ski. The effective stiffness of the liquid system can beadjusted to a suitable value by making some part of the system moreelastic. (Alternatively, a gaseous system can be adjusted to a suitablevalue by making some part of the system stiffer.) One illustrativesystem for doing this is to provide the device of FIG. 2 with bothliquid and gas fluid. In that system, a liquid fluid pressure medium isprovided along the bottom portion of housing 110 and a gaseous fluidpressure medium is disposed between the liquid fluid pressure medium andtop member 200. Preferably, either or both the liquid fluid pressuremedium and the gaseous fluid pressure medium are contained by a fluidbag although no container means or other container means such as adiaphragm may be employed to separate and contain the liquid and gaseousfluid pressure media. The fluid bags are chosen for compatibility withthe fluid pressure medium they are to contain, normally nitrile rubberfor general use. As one example is a FIG. 2 device, operated with about33% of the pressure chamber being occupied by oil contained in a fluidbag and the remainder of the fluid pressure chamber being charged withair (contained by a fluid bag) to about 18 psi.

Changing the physical parameters of the fluid pressure means--volume,for example--is yet another method for adjusting the stiffness of eithera liquid or a gas based fluid pressure medium. For example, a fluidpressure medium charged system of FIG. 2 can be provided with means forchanging the response characteristics of the fluid pressure medium inthe system to impact forces. FIG. 6 shows in schematic form, one such"fluid softening system" 610 comprising the force modulating device ofFIG. 2, shown here in functional block 620, and functional blocks 630and 640 as hereinafter described.

In a first such "fluid softening" system 610, functional block 620,which contains the fluid system of FIG. 2, charged here with liquidfluid pressure medium (although it will be appreciated that such asystem 610 can be adapted to lend itself to charging with a gaseousfluid pressure medium), has connected thereto one channel member 632(although it will be appreciated that more than one channel member canbe used with this system) shown here in functional block 630 which inturn is connected to a reservoir 642 shown here in functional block 640.The channel member, having about a 2.38 mm diameter, is connected to alower portion of the reservoir, illustratively rectangular in volume,having about a 645 square mm area opening and a depth of about 4.76 mm.The reservoir opens along the upper surface of the ski device with theopening being enclosed by an elastic diaphragm 644. Pressure chamber 300of the FIG. 2 fluid system of functional block 620, channel member 632and reservoir 642 are charged with a liquid fluid. When top member 200extends into bore 120 of the liquid charged FIG. 2 fluid system offunctional block 620 as a result of an impact force, liquid fluidpressure medium is caused to be communicated to reservoir 642 and urgedagainst the elastic diaphragm 644. Stretching of the diaphragm inresponse thereto enlarges the volume of reservoir 642, and hence thevolume of the fluid softening system 610 containing the liquid fluidpressure medium. The cooperation of pressure chamber 300 and reservoir642 in this way softens the liquid charged FIG. 2 fluid system offunctional block 620.

It will be appreciated that in such a fluid softening system 610 anenclosed reservoir with no elastic sidewall can be used in place of theelastic-sidewalled reservoir above described. In such a nonelasticwalled reservoir, the reservoir can be provided with impact forcemodulating means--for example, a gaseous charged fluid bag securedinside the reservoir away from the reservoir opening to the channelmember--which modulates the forces imparted to the top member that arecommunicated to the reservoir by fluid pressure medium through channelmember 632. Alternatively, if the FIG. 2 system is charged with agaseous fluid pressure medium, the fluid bag in the reservoir can becharged with a liquid fluid pressure medium.

It will also be appreciated that in these and other reservoir-interfacedFIG. 2 force modulating systems 610 (including such systems where thereservoir is not remotely located from the pressure chamber), therebound of the top member can be controlled by providing along the flowline between the pressure chamber and the reservoir one or more valvescapable of controlling the movement of the fluid pressure medium withinthe system 610. Such valves can be calibrated to cause a certainresistance to the passage of fluid pressure medium.

As one example in a two channel member 632 system 610, the first channelcan be provided with a first one-way valve substantially allowing onlyflow from the pressure chamber to the reservoir at a first resistanceand the second channel can be provided with a second one-way valvesubstantially allowing only flow from the reservoir to the pressurechamber at a second resistance that is less than the resistance of thefirst valve. This two valve system provides for greater resistance oncompression strokes of the core assembly than on rebound strokes. As oneexample in a one channel member 632 system, a ball type valve can beoriented within channel member 632 so as to provide more resistance oncompression than on rebound. In this example, a free ball valve isfitted within the channel member 632, the ball being free to moveaxially within the valve body. The valve is fitted into the channel (inthis illustration the channel runs lengthwise with respect to the skiand terminates behind the FIG. 2 fluid system) so that the downstreamseat terminates away from and the upstream seat terminates toward thepressure chamber of the FIG. 2 fluid system. With the skis facingdownhill, gravity forces the ball against the upstream seat, the openposition of the valve, which allows minimally restricted flow of fluidpressure medium through the channel member. A pressure differentialacross the valve created by the plunging of the top member (of the FIG.2 fluid system) into the pressure chamber forces the ball into thesubstantially closed position against the downstream seat which isconfigured so that in this position the valve allows some but verylittle flow of fluid pressure medium through the channel member.

In a second "fluid softening" system 610 accomplished through parametricchanges being made to the fluid pressure means, the FIG. 2 fluid systemrepresented by functional block 620 of FIG. 6 is charged here with agaseous fluid pressure medium (although it will be appreciated that sucha system 610 can be adapted to lend itself to charging with a liquidfluid pressure medium), functional block 630 again comprises channelmember 632 and functional block 640 here comprises a valve controlsystem with transducer feedback 700. As shown in FIG. 7, the controlsystem 700 comprises an electronic control valve 710, reservoir 720,first and second plumbing flow lines 730, 732, control circuit 740,transducer circuit 750 and power source 760.

As shown in FIGS. 7,8, valve 710 comprises a solenoid operatedmicrominiature valve having low power and small space requirements. Forski climates at or above about the freezing point temperature,illustratively, a 11/4"×1/2", 1.5 watt, 12 volt, 0-50 psi, 2- waynormally closed sub-miniature solenoid valve with 0.03 orificemanufactured by Asco/Angar is used. Illustratively, the valve is mountedon a nonmovable member of the ski device behind binding unit. Reservoir720 is a rectangular 10 cc metallic container for receiving and holdingfluid pressure medium. A manual bleed port 722 is provided at a lowerend thereof to permit bleeding of fluid pressure medium from thereservoir. Illustratively, the reservoir is mounted on a nonmovablemember of the ski in close proximity to the valve. The reservoir isconnected to the valve by first plumbing flow line 730. The secondplumbing flow line 732 connects the valve to an open end 634 of thechannel member 632 along the surface of the ski.

Transducer circuit 750 comprises an immersion type temperaturetransducer 752 and a signal conditioning circuit 754. The transducer isimmersed into the fluid pressure medium of the pressure chamber of theFIG. 2 fluid system represented by functional block 620 through housing110 where the sensor is mounted through a pressure sealed opening.Illustratively, a threaded mounting allows for compression sealing bymeans of a gasket or 0 ring between the housing and the mounting boss.Wire means 756 from the transducer are run through bottom member of theski device and are brought out of the bottom member behind functionblock 620 so as to terminate near the valve 710 and the reservoir 720 atthe signal conditioning circuit 754. Signal conditioning circuitcomprises a voltage follower circuit which has an output voltage thatfollows the input voltage. It receives the instantaneous signal fromtemperature transducer 752 and generates an amplified, filtered signalat its output. By isolation of the transducer from the load atcomparator 742, as hereinafter described, the conditioning circuitprevents undesired interactions or loading effects between thetransducer and the load.

Control circuit 740 comprises a comparator circuit 742, a monostablemultivibrator 744, and a power amplifier 746. Comparator 742 is aninverting level detector which compares the instantaneous signal fromsignal conditioning circuit 754 with a reference signal. The referencesignal is set to the voltage level generated by the transducer circuit750 at the critical temperature, as hereinafter described. Whenever theinput signal to the comparator changes from less than the reference togreater than the reference (or vice-versa), the output of the comparatorabruptly changes state. The output from the comparator, logic high afterreset, is applied to the monostable multivibrator 744. The monostablemultivibrator is a monostable multivibrator circuit which in response toa negative trigger pulse from the comparator 742 generates a voltagepulse with a width having a predetermined time, illustratively, 3seconds. Power amplifier 746 comprises a power amplifier circuit. Itreceives the signal from the monostable multivibrator and generates apower amplified signal at its output. The output from the poweramplifier drives the valve.

Power source 760 comprises a power pack 762 and a voltage regulator 764.Power pack 762 generates electrical energy for powering control circuit740, transducer circuit 750 and valve 710. Illustratively, power packcomprises a 12 volt source comprising a series connection of 1.5 voltalkaline-manganese dioxide cell systems. Alternatively, other cellsystems mountable on the ski and meeting the power requirements of thecontrol circuit, the transducer circuit and the valve can be used. Poweramplifier 746 is powered directly off power pack 762. The voltage levelput out by the power pack is stepped down through voltage regulator 764for powering transducer circuit 750, comparator 742 and monostablemultivibrator 744.

Signal conditioning circuit 754, control circuit 740, and voltageregulator 764 are mounted on a substrate 770 of electrically insulatedmaterial such as a plastic. The power amplifier 746 and voltageregulator 764 are mounted to the substrate 770 through metal heat fins772,773, respectively, which serve to dissipate heat generated by thesedevices. Substrate 770, power pack 762, valve 710 and reservoir 720 aremounted to a bottom panel 782 of a housing 780 which in turn ispreferably mounted on a nonmovable member of the ski. The housing ispreferably made from hard plastic so as to withstand impacts experiencedduring skiing and to insulate the components contained inside thehousing from the environment. Alternatively, any material or combinationof materials that meet the above impact and electrical requirements canbe used. The housing is provided with a lid member 783 which can beopened, allowing the electrical elements inside the housing to bereached from outside of the housing but which, when closed, providescomplete electrical insulation and insulation of the elements from theenvironment. Hinges 784, 786 on the lid member 783 allow housing 780 tobe so opened. The housing is configured so as to allow adequate heatdissipation of the elements internal to the housing that are mounted tothe bottom panel 782 of the housing. A snap member 787 on lid 783 mateswith a catch member 788 provided on the bottom panel 782 of the housingwhen the lid member is in the closed position so as to keep the lid ofthe housing snap-tight closed when the ski device is stored or in use.All electrical leads are shrink wrapped with plastic tubing and terminalconnections are electrically insulated from the environment.

In this system, gaseous fluid pressure medium in the FIG. 2 pressurechamber represented by function block 620 is hardened by heat producedby the plunging action of the FIG. 2 top member in the pressure chamber.When the temperature of the gaseous fluid pressure medium in thepressure chamber reaches the critical temperature, as hereinafterdescribed, the valve 710 is actuated so as to allow the gaseous fluidpressure medium to communicate with the reservoir 720. Slightdecompression of the pressure chamber caused by the fluid pressuremedium now occupying the combined larger volume of the reservoir and thepressure chamber causes the gaseous fluid pressure medium in thepressure chamber to soften, resulting in a softer ski.

Control of gas flow out of the pressure chamber is realized by the valve710. Without excitation of the valve, the valve is closed, thuspreventing gaseous fluid pressure medium in the pressure chamber fromflowing into the reservoir, but permitting gaseous fluid pressure mediumalready in the reservoir to be vented off through bleed port 722.Activation of the control valve by an electrical signal from the controlcircuit 740 permits gaseous fluid pressure medium to flow into thereservoir and cause the pressure level in the pressure chamber to relax.(It will be appreciated that instead of venting fluid pressure mediuminto the reservoir, such system can be adapted to vent the fluidpressure medium into the atmosphere.)

The critical temperature in the control system is predetermined as thetemperature at which the response characteristics of the fluid pressuremedium are deemed advantageous to be changed. Illustratively, in asystem having a working volume up to the valve of about 90 cc (with avolume after the valve and including reservoir 720 of about 10 cc)fabricated so as to be chargeable to 30 psi operating in about a zerodegrees Centigrade climate, activation of the valve 710 at a criticaltemperature of about 27.5 degrees Centigrade softens the pressure of thefluid pressure medium from about 33 psi at the critical temperature tounder about 30 psi.

In the illustrative embodiment of the present invention shown in FIG. 2,bottom member 100 defines in a portion thereof housing 110 forming bore120 on an inside surface and top member 200 comprises the core assembly210 slidably disposed within the bore 120 and the top layer 260engageable with the core assembly 210. Alternatively and as shown inFIG. 9, in ski device 1010, a bottom member 1100 is fabricated so as toserve as the top portion of the ski device and a top member 1200 isfabricated so as to serve as the bottom portion of the ski. Ski device1010 comprises many of the same elements as that of FIG. 2 and suchelements bear the same numbers, increased by 1000. In this illustration,the top member 1200 now serving as the bottom surface is not providedwith a protective cosmetic surface layer as in FIG. 2 but insteadfurther comprises a low friction running surface 1130 and edges 1140 andthe bottom member 1100 now serving as the top surface is not providedwith running surface and edges, but instead further comprises aprotective cosmetic layer 1264.

In addition, although the top member of the ski device of the presentinvention has been described in terms of its providing a top or bottomsurface to the ski device (see FIGS. 2,9, respectively, for example), itwill be appreciated that in the present invention the exposed portionsof the ski device lying above its running surface can be provided withan elastic case--made of rubber, for example--which prevents moisture,air flow, objects, and other elements external to the ski frompenetrating the inner recesses of the ski device that are reachable bygoing between the top and bottom members of the ski device.Illustratively, such an elastic overlay, which illustratively isadhesively secured along its edges to the ski device, has sufficientelasticity to permit the top member to move with respect to the bottommember. In this embodiment, the top member is incorporated within theski.

Moreover, it will be appreciated from FIG. 3, where housing 110 portionis fabricated separately from the bottom member and then bonded to thebottom member, that such separately fabricated housing can in fact serveas a body member of a force modulating device, for use in a ski device,in which the top member 200 serves as a movable member of the forcemodulating device, movably interconnected to the body member, and inwhich fluid pressure means, illustratively comprising fluid containmentmeans and a fluid pressure medium, is disposed between the body memberand the movable member of the force modulating device for floating themovable member with respect to the body member and controlling therelative movement between the movable member and the body member.Incorporated into the ski device, the controlled movement of the movablemember relative to the body member provided by the fluid pressure meanscauses impact forces that are imparted to the force modulating deviceand hence ski device in which it is incorporated to be so modulated asto allow for good ski performance in terms of spring-action, smoothride, handling, and service life.

It will be appreciated that such a force modulating device can be soincorporated into the ski device that its movable member provides a topor bottom component to the ski device--as in FIGS. 2,9, for example. Orit can be so incorporated that its body component provides a top orbottom component to the ski device. Alternatively, the entire forcemodulating member of the present invention (i.e., both movable and bodymembers), can be incorporated within the ski device. Incorporating intothe ski device more than one such device of like or different fluidpressure means, with the sprung and unsprung portions of the devicebeing "weighted" appropriately, can further tailor the dynamic responseof the ski to particular impact forces.

It will be appreciated that there exist other varying permutations andcombinations for dimensioning the force modulating device of the presentinvention. For example, although the depth of the top member has beenillustrated as uniform therethrough, such depth can be made to varyalong the surface of the ski device. Similarly, the depth of the borecan be made to vary along the length of the ski device. Other varyingpermutations and combinations for dimensioning of the top member andbore of the force modulating device can be used so as to provide adesired stiffness to the ski device.

It will also be appreciated that a fluid pressure supply source of smalldimensions can be mounted on the ski device. The fluid pressure supplysource can be interfaced to inlet port 310 so as to allow for manual, oras set forth below, automatically controlled, regular or periodiccommunication of fluid pressure medium from the fluid pressure supplysource to the pressure chamber.

It will further be appreciated that the valve control system withtransducer feedback 700 can employ any control means--limited only bythe space requirements available on the ski and, if of an electricaltype, the power requirements imposed by the power source useable on theski. Such control means can, for example, monitor force, pressure,velocity, temperature and other physical parameters through sensingmeans located in the pressure chamber and elsewhere throughout the skiand can control the fluid pressure medium in response thereto. As oneexample, control means can control communication between an on-boardfluid pressure supply source, automatically, allowing there to beirregular or periodic communication of fluid pressure medium from saidsource to the pressure chamber during a ski run. If more than one fluidpressure supply source is mounted to the ski, each at a differentcharge, on-board control means can, for example, allow there to beautomatic irregular or periodic communication between one or more ofsuch fluid pressure supply sources and the pressure chamber--orchambers, if more than one such force modulating device is used in theski device--during a ski run based upon information the control meansreceives from on-board sensing means.

While the invention has been described in conjunction with specificembodiments, it is evident that numerous alternatives, modifications,and variations will be apparent to those skilled in the art within thespirit and scope of the invention described above.

I claim:
 1. A ski body, comprising:an exposed top surface; a groundcontacting bottom surface; a body member disposed in interbondingrelationship between said exposed top and ground contacting surfaces andhaving an immovable bottom surface and a top surface and defining acavity having an opening along said immovable bottom surface; a movablemember extending into said cavity, said movable member having a bottomsurface which forms a movable bottom surface to said body member; meansadapted to said ski body for limiting the downward movement of saidmovable member; sealed compressible fluid under pressure disposedbetween said body member and said movable member for controlling therelative movement of said movable member with respect to said bodymember.
 2. The ski body of claim 1 wherein said sealed compressiblefluid is a gas.
 3. The ski body of claim 1 wherein said sealedcompressible fluid is a liquid.
 4. The ski body of claim 1 wherein saidsealed compressible fluid is a combination gas and liquid.
 5. The skibody of claim 1 wherein said compressible fluid is sealed by the tightcooperation of said movable member with the wall of said cavity.
 6. Theski body of claim 1 wherein said compressible fluid is sealed by a fluidbag contained within said cavity.
 7. The ski body of claim 1 whereinsaid compressible fluid is sealed by a resilient seal disposed betweensaid movable member and the wall of said cavity.
 8. The ski body ofclaim 7 wherein said resilient seal is mounted to said movable member soas to be urged by said movable member against the wall of said cavity.9. The ski body of claim 7 wherein said resilient seal is mounted to thewall of said cavity so as to be urged by the wall of said cavity againstsaid movable member.
 10. The ski body of claim 1 further comprising aninlet port openning at a first end to said cavity and at a second endalong an outside surface of said ski body.
 11. The ski body of claim 10wherein said inlet port is a pressure valve.
 12. The ski body of claim10 wherein said second end of said inlet port is adaptable forconnection to a pressure supply source.
 13. The ski body of claim 10wherein said outside surface of said ski body along which said secondend of said inlet port opens is an outer sidewall of said ski body. 14.The ski body of claim 6 further comprising an inlet port opening at afirst end to the inside of said fluid bag and at a second end along anoutside surface of said ski body.
 15. The ski body of claim 14 whereinsaid inlet port is a pressure valve.
 16. The ski body of claim 14wherein said second end of said inlet port is adaptable for connectionto a pressure supply source.
 17. The ski body of claim 1 wherein saidmeans for limiting the downward movement of said movable member is astop provided on said movable member which is movably received by anoutwardly stepped portion of said cavity.
 18. The ski body of claim 17wherein said stop is a sidewardly extending flange which isdimensionally smaller than said outwardly stepped portion and whichextends sidewardly into said outwardly stepped portion so as to belongitudinally movable within said outwardly stepped portion.
 19. Theski body of claim 1 further comprising structural enhancement meansbetween said movable member and said body member for resisting saidmovable member from rolling, pitching, or yawing within said cavityduring turning motions of said ski body.
 20. The ski body of claim 19wherein said structural enhancement means is provided by the cooperationof said movable member with the wall of said cavity.
 21. The ski body ofclaim 19 wherein said structural enhancement means is provided byproviding said body member with at least one vertical guide post whichextends longitudinally downward from a bottom surface of said cavity andinto said cavity, and defining at least one longitudinal opening on atop surface of said movable member for movably receiving said verticalguide post.
 22. The ski body of claim 1 wherein said ground contactingbottom surface comprises a layer of elastic material disposed below saidmovable and immovable bottom surfaces of said body member and saidexposed top surface comprises a cosmetic top layer disposed above saidtop surface of said body member.
 23. The ski body of claim 1 whereinsaid ground contacting bottom surface comprises a first running surfacelayer disposed below said movable bottom surface of said body member anda second running surface layer disposed below said immovable bottomsurface of said body member and said exposed top surface comprises acosmetic top layer disposed above said top surface of said body member.24. A ski body, comprising:an exposed top surface; a ground contactingbottom surface; a body member disposed in interbonding relationshipbetween said exposed top and ground contacting bottom surfaces andhaving an immovable bottom surface and a top surface and defining aplurality of cavities opening along said immovable bottom surface; aplurality of movable members extending into said cavities, said movablemembers each having a bottom surface which forms a movable bottomsurface to said body member; means adapted to said ski body for limitingthe downward movement of said movable members; a sealed compressiblefluid under pressure disposed between said body member and said movablemembers for controlling the relative movement of said movable memberswith respect to said body member.
 25. The ski body of claim 24 whereinsaid sealed compressible fluid comprises a plurality of sealedcompressible fluids, one each of said sealed compressible fluids beingdisposed between said body member and one each of said respectivemovable members for controlling the relative movement of said movablemembers with respect to said body member.
 26. The ski body of claim 25wherein said ground contacting bottom surface comprises a first runningsurface layer disposed below said movable bottom surface of said bodymember and a second running surface layer disposed below said immovablebottom surface of said body member and aid exposed top surface comprisesa cosmetic top layer disposed above said top surface of said bodymember.
 27. The ski body of claim 25 wherein said ground contactingbottom surface comprises a layer of elastic material disposed below saidmovable and immovable bottom surfaces of said body member and saidexposed top surface comprises a cosmetic top layer disposed above saidtop surface of said body member.
 28. The ski body of claim 25 wherein atleast one of said sealed compressible fluids is a gas.
 29. The ski bodyof claim 25 wherein at least one of said sealed compressible fluids is aliquid.
 30. The ski body of claim 25 wherein at least one of said sealedcompressible fluids is a combination of gas and liquid.
 31. The ski bodyof claim 25 wherein at least one of said compressible fluids is sealedby the tight cooperation of said movable member with the wall of saidrespective cavity.
 32. The ski body of claim 25 wherein at least one ofsaid compressible fluids is sealed by a fluid bag contained within saidrespective cavity.
 33. The ski body of claim 25 wherein at least one ofsaid compressible fluids is sealed by a resilient seal disposed betweensaid respective movable member and the wall of said respective cavity.34. The ski body of claim 25 further comprising at least one inlet portopenning at a first end to one said cavity and at a second end along anoutside surface of said ski body.
 35. The ski body of claim 34 whereinsaid inlet port is a pressure valve.
 36. The ski body of claim 34wherein said second end of said inlet port is adaptable for connectionto a pressure supply source.
 37. The ski body of claim 34 wherein saidoutside surface of said ski body along which said second end of saidinlet port opens is an outer sidewall of said ski body.
 38. The ski bodyof claim 32 further comprising an inlet port opening at a first end tothe inside of said fluid bag and at a second end along an outsidesurface of said ski body.
 39. The ski body of claim 38 wherein saidinlet port is a pressure valve.
 40. The ski body of claim 38 whereinsaid second end of said inlet port is adaptable for connection to apressure supply source.
 41. The ski body of claim 25 wherein said meansfor limiting the downward movement of at least one of said movablemembers is a stop provided on said movable member which is movablyreceived by an outwardly stepped portion of said respective cavity. 42.The ski body of claim 41 wherein said stop is a sidewardly extendingflange which is dimensionally smaller than said outwardly steppedportion and which extends sidewardly into said respective outwardlystepped portion so as to be longitudinally movable within said outwardlystepped portion.
 43. The ski body of claim 25 further comprisingstructural enhancement means between at least one of said movablemembers and said body member for resisting said movable member fromrolling, pitching, or yawing within said respective cavity duringturning motions of said ski body.
 44. The ski body of claim 43 whereinsaid structural enhancement means is provided by the cooperation of saidmovable member with the wall of said respective cavity.
 45. The ski bodyof claim 43 wherein said structural enhancement means is provided byproviding said body member with at least one vertical guide post whichextends longitudinally downward from a bottom surface of said cavity andinto said cavity, and defining at least one longitudinal opening on atop surface of said movable member for movably receiving said verticalguide post.